Four indications that Spring is on the horizon

It still looks and feels like winter across much of the United States, but meteorological spring has already begun, and astronomical spring is only a couple of weeks away, beginning on March 20.

In a recent AccuWeather.com poll, our readers responded to the question "What are you looking forward to this spring?" and more than 48 percent of people weighed in with "warmer weather replacing the cold, snowy winter!"

While cold weather is lingering into March, it is becoming less extreme and temperatures will continue to trend up in coming weeks. Along with rising temperatures, the following are four signs of spring to anticipate with the changing season.

1. Groundhogs Make Their Grand Appearance

Punxsutawney Phil may be the most famous of all the groundhogs, particularly those of the weather-prognosticating variety.

Groundhogs emerge from their burrows around Feb. 4 each year in southeastern Pennsylvania, where Professor Emeritus of Biology Stam Zervanos at Penn State University lives.

"Hibernation has fitness value because it enhances survival by saving energy during times of limited food availability," he said.

Some males and females emerge in early February and by early March, they all emerge to mate, Zervanos said.

They don't get along most of the time, but February is the month where they start getting along in time for March mating.

Young groundhogs born in April arrive just in time for May's food supply, which helps them get an early start of surviving winter hibernation, Zervanos said.

2. Great-Horned Owls and Chipmunks Emerge

The first sign of spring is the lengthening of the daylight, known as photoperiod.

When the days get longer, animals respond via hormone triggers, and reproductive activity starts to slowly develop, New York State Department of Environmental Conservation Chief Biologist Gordon Batcheller said.

"The earliest harbinger is great-horned owls. They start nesting as soon as January, with February being key," Batcheller said. "Many furbearers (such as coyotes and fox) 'pair up' in the depths of winter, and certainly by now, they have been bred and their pups are growing in utero."

As far as "hibernating" animals go, the appearance of Eastern chipmunks is a good sign that the weather is truly turning, Batcheller said.

"They are a true hibernator; they are abundant and easily seen. When you see a chipmunk, one knows that spring is truly coming," he said.

Bears also make their appearances, but they are somewhat active in their dens during the late fall and winter months.

"During this denning period, the sows give birth to their cubs, and they will wake and nurse during the denning period. They do not eat while denned up, nor do they drink, defecate or urinate, but they will nurse their cubs," he said.

3. Flowers Burst Onto the Scene

Melting snows signal the arrival of the first spring flowers.

One of the first of those flowers to appear is the blue Siberian squill, or Scilla, part of the selection of early blooming bulbs. The bulb produces scented blue flowers, the National Gardening Association said.

Crocuses are also among the first flowers of spring in a variety of colors including blue, yellow and white, the association said.

Early flowers need to be hardy because of the changing weather patterns in the spring.

"Since snow cover can still be present across the northern states into April and the jet stream has not fully retreated northward into Canada, the source of cold air is still in relatively close proximity to the central and southern United States," AccuWeather.com Meteorologist Mike Doll said. "If a dip in the jet stream develops, this cold air can plunge southward and lead to big temperature swings from one day to the next."

4. Severe Weather Ramps Up

In spring, the jet stream gradually shifts north. This allows a warmer air to infiltrate the southern U.S. from the West and Southwest, Doll said.

The initial severe threat is limited to the Deep South in early March, but by the end of the month, the threat grows in the ArkLaTex, Oklahoma and central Alabama to east-central Georgia, the Severe Prediction Center said.

"Throughout spring, the sea surface temperatures of the Gulf of Mexico rise," Doll said. "As a result, the amount of low-level moisture that is available increases. The warm, moist air provides fuel for thunderstorms, and this type of air mass gradually spreads north as spring progresses as the jet stream shifts northward."

As the spring progresses, severe weather most frequently focuses on the traditional tornado alley, from Dallas to Des Moines, Iowa, as well as the Carolinas and the Ohio Valley, according to NWS data.